1. Field of the Invention
The present invention relates to an antenna device and an electronic apparatus, and particularly relates to, for example, an antenna device including an antenna unit, a matching circuit unit, a transmission line unit, and a connecting portion and an electronic apparatus including the antenna device.
2. Description of the Related Art
In electronic apparatuses (such as mobile devices, for example) having a housing which contains an antenna and a circuit board, a structure in which the antenna is attached to the inner surface of the housing and a conductor on the circuit board is connected to the antenna by a spring pin or the like, is known.
For example, Japanese Unexamined Patent Application Publication No. 2012-231386 discloses a communication apparatus having a housing which contains an antenna and a circuit board. The communication apparatus has a configuration in which the antenna disposed on the inner surface of the housing is connected to a conductor on the circuit board by a connecting member, such as a spring pin.
With the recent miniaturization and sophistication of electronic apparatuses, it has become difficult to create sufficient space, in a housing of an electronic apparatus, for arranging a matching circuit and a transmission line or the like.
In the configuration disclosed in Japanese Unexamined Patent Application Publication No. 2012-231386, a matching circuit and other components of the antenna are mounted on the circuit board of small size. Therefore, the degree of freedom in designing the arrangement of the matching circuit and other components is lowered. Also, as described above, the conductor on the circuit board is connected to the antenna by the connecting member, such as a spring pin. This not only causes a loss in the connecting member, but also makes it difficult to achieve impedance matching because the length of a line between the antenna and the matching circuit is long. Moreover, since a conductive pattern of the antenna and the connecting member, such as a spring pin, are close to each other, stray capacitance between the conductive pattern and the connecting member is formed therebetween. This leads to degraded antenna characteristics, or causes changes from original antenna characteristics after the antenna is mounted onto the housing.